 /*******************************************************************************
  * Copyright (c) 2004, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.registry;

 import org.eclipse.core.runtime.InvalidRegistryObjectException;

 /**
  * A handle is the super class to all registry objects that are now served to users.
  * The handles never hold on to any "real" content of the object being represented.
  * A handle can become stale if its referenced object has been removed from the registry.
  * @since 3.1.
  */
 public abstract class Handle {
     protected IObjectManager objectManager;

     private int objectId;

     protected int getId() {
         return objectId;
     }

     Handle(IObjectManager objectManager, int value) {
         objectId = value;
         this.objectManager = objectManager;
     }

     /**
      * Return the actual object corresponding to this handle.
      * @throws InvalidRegistryObjectException when the handle is stale.
      */
     abstract RegistryObject getObject();

     public boolean equals(Object object) {
         if (object instanceof Handle) {
             return objectId == ((Handle) object).objectId;
         }
         return false;
     }

     public int hashCode() {
         return objectId;
     }
 }

